On Thursday, they're due to appear together at a student rally for academic freedom at the University of Colorado at Boulder.
Churchill, Ayers and writer-activist Derrick Jensen are to speak at an event titled, "Forbidden Education and the Rise of Neo-McCarthyism."
Churchill was a tenured professor of ethnic studies at Colorado University until he was fired on plagiarism charges in July 2007. He denies misconduct and is soon due to go to court in an attempt to get his job back.
In his lawsuit, he claims the university was looking for reasons to fire him because of his comments about the Sept. 11, 2001, terrorist attacks.
"I'm feeling very good about the case I'm going to present" in the lawsuit, Churchill said Wednesday. He said he couldn't discuss specifics.
In an essay and a follow-up book, Churchill argued that the attacks were a response to a history of U.S. abuses. He said the victims of the World Trade Center collapse were "little Eichmanns," referring to Holocaust organizer Adolf Eichmann.
Churchill said Eichmann was a bureaucrat who carried out policies that were planned by others but was still responsible for his actions. The essay triggered a national firestorm and calls for his dismissal.
Ayers was a co-founder of the Weather Underground, a radical anti-war group that claimed responsibility for a series of bombings, including explosions at the Pentagon and U.S. Capitol that didn't kill anyone.
He was a fugitive for years. After surrendering in 1980, charges against him were dropped because of prosecutorial misconduct.
Ayers, an education professor at the University of Illinois at Chicago, said his schedule didn't allow him to be interviewed Wednesday.
Churchill said he knew Ayers in 1970 when they were both active in the anti-Vietnam war movement, but he said they haven't spoken since. Churchill said he wasn't a member of the Weather Underground.
During the presidential campaign, John McCain's running mate, Alaska Gov. Sarah Palin, resurrected Ayers' radical past when she accused then-candidate Barack Obama of "palling around with terrorists."
Obama and Ayers served together on the board of a Chicago charity, and Ayers hosted a meet-the-candidate session for Obama at his home in the mid-1990s when Obama first ran for office.